Re: [RFC][PATCH 1/2] memcg: Ensure every task that uses an mm is in the same memory cgroup

From: Tejun Heo
Date: Mon Jun 04 2018 - 14:47:48 EST


Hello, Michal.

On Mon, Jun 04, 2018 at 03:01:19PM +0200, Michal Hocko wrote:
> > On Fri, Jun 01, 2018 at 01:11:59PM -0500, Eric W. Biederman wrote:
> > > Widening the definition of a process sounds good. The memory control
> > > group code would still need a way to forbid these in cgroup v1 mode,
> > > when someone uses the task file.
> >
> > Yeap, you're right. We'll need memcg's can_attach rejecting for v1.
>
> Do we really need? I mean, do we know about any existing usecase that
> would need this weird threading concept and depend on memory migration
> which doesn't really work?

I thought the requirement is from the ->owner change so that the
association doesn't become 1:N, right?

Thanks.

--
tejun